Concrete b15: characteristics, scope and preparation

Based on its average density, concrete is subdivided into a number of classes, which start at B3.5 and end at 80. But the most popular among them is concrete grade B15. Its strength is 196kgs / cm ?, which corresponds to the type M200.

Consider this material in more detail.

General characteristics of concrete B15 M200

Scope and composition

This solution is widely used in the field of individual construction.

In particular, it is used for the following purposes:

• foundation casting - it can be tiled, tape, and pile-grillage constructions;

• making concrete stairs - concrete M200 + B15 has sufficient strength to build a reliable and durable product;
• padding sites - created sites can withstand not only pedestrian traffic, but also the placement of vehicles, for example, a car;

• curbstone installation - the mixture used allows to obtain a high-quality concrete pad needed for the installation of road elements.

The composition of concrete B15 includes cement, gravel and sand. They are among themselves in proportion 1: 4,8: ​​2,8. In addition to them in the solution may be special additives. More information about the components of this mixture will tell you the following table.

Tip! Used cement must be stored in a sealed package. Otherwise, moisture contained in the ambient air will get into it, and the material will harden.

The main indicators of concrete type B15 M200

Any concrete mix is ​​characterized by two main indicators, brand and class. So, B15 is a class that is characterized by a numerical coefficient of 0.95. This number means that the property that is set by this class is observed in 95% of cases, and only 5% of cases it may not be fulfilled.

In turn, M200 is a brand, the main indicator of which is the resistance of the product to axial compression, measured in kg / cm ?. It characterizes the strength of concrete B15.

The following table will provide you with additional information on the characteristics of this composition.

Preparation of solution B15

Composition B15 M200 can be purchased at specialized firms in ready-made form. In this case, the price will be approximately 3600 rubles per 1m? material. But you can cook it yourself.

Requirements in accordance with which this concrete mix has to be made are contained in GOST 26633-91. So, the used crushed stone from natural stone must have a grade not lower than 300, and the applied sand must have a modulus of fineness 2.0.

Speaking about the creation of a solution of class B15, it should be noted that in its composition there may be cement brand M400 or M500. Depending on this, the volume fractions of the components of the mixtures created will differ somewhat.

When using a 200 liter mixer, the proportions are as follows:

1. M400 cement - 10 liters, sand - 25 liters, crushed stone - 40 liters. The resulting solution is 54 liters;
2. M500 cement - 10 liters, sand - 32 liters, crushed stone - 49 liters. The resulting solution is 62 liters.

  Tip! In order for the resulting mixture to have all the required properties, it is necessary to strictly adhere to the established proportions.

Instructions for mixing the solution is as follows:

1. water is poured into the mixer, after which the cement is gradually poured into it;
2. sand is gradually added to the mixture, then gravel;
3. after reaching a uniform consistency of the composition, it can be applied.

Recommendations for pouring solution B15

For proper potting, use the following guidelines:

• the concrete mixer should be installed as close as possible to the place where concreting will be carried out - the mixture hardens quite quickly, therefore the delivery distance should be the shortest;
• the concrete mass B15 must be poured in from a height not exceeding 1 meter - otherwise, separation of the composition may occur;
• it is better to fill with the use of the gutter - thanks to it the work will become more accurate and accurate;

• this process can be started only under favorable atmospheric conditions — a temperature not lower than + 5 ° and no rain;
• if possible, all the work needs to be done in a single approach - this will make it possible to obtain a uniformly durable material;
• if you still have to take a break, it should not exceed 3 hours - if this interval is exceeded, you need to do the following with your own hands. Hammer the top layer of the filled surface, then clean it and pour it with water. After that, you can start pouring the next portion of the solution;
• instead of a building vibrator, a conventional steel bar can be used to seal the cast-in composition - this is permissible with a concrete layer depth of no more than 20 centimeters. If the density of concrete B15 has increased to a plastic state, then for its tamping you will need an expanded wooden stick at the end;
• those areas of the surface, which the reinforcement passes through, in addition to compaction, also need to be tapped;
•  in hot conditions, the surface of the concrete should be sprayed periodically with water - this will prevent the material from cracking. To protect it from rain, you can cover the surface with polyethylene.

Conclusion

Sand concrete class B15 M200 is widely used for pouring foundations, creating concrete stairs, pouring platforms and installing curbs. It has a strength of 196 kg / cm ?. Consists of cement, sandy material and crushed stone, which are in the proportion of 1: 4.8: 2.8.

You can get more details about this concrete from the video in this article.